Ultrasonic surgical probe, assembly, and related method

ABSTRACT

An ultrasonic surgical probe has an elongate shaft and a probe head that is enlarged to extend laterally or transversely in two opposed directions relative to the shaft The head is formed with a recess or cavity facing laterally in a third direction relative to the shaft and the axis. Where the head lies in a plane, owing to its lateral enlargement or extension, the recess or cavity faces in a direction perpendicular to that plane. The recess or cavity is defined in part by an inclined floor or base surface contiguous at a proximal end with the shaft. The recess or cavity is defined in part by a peripheral wall extending only partway around the recess or cavity, along a distal side and two lateral sides thereof. The cavity or recess is closed on a proximal side by the inclined surface and the shaft.

BACKGROUND OF THE INVENTION

This invention relates to an ultrasonic surgical probe. This inventionalso relates to an assembly of a probe and a sheath. The inventionadditionally relates to an associated method for operating on a surgicalsite, exemplarily to reduce biofilm on a wound site particularly a woundsite that is being debrided to remove necrotic tissue.

Chronic wound infection represents a significant healthcare problemworldwide. Often the end objective of wound healing is the objective fornew therapeutic options. Yet chronic wounds compromise a number ofdifferent and complex conditions that each interferes with the healingprocess. For example, a chronic wound can comprise necrotic tissue inneed of debridement, bacterial infection in need of antimicrobial agentsand compromised vasculature that impedes the normal healing process.

One element of the chronic wound infection condition that impedeshealing is the formation of biofilm. Biofilm is the result of planktonicbacteria forming together and secreting exopolysaccharide (EPS) toadhere and protect the colonizing community. At the height of formation,EPS can make up between 75-90% of the total biofilm composition (Regt).Biofilm inhibits healing by creating an optimal condition for bacteriato grow, while simultaneously preventing antimicrobial agents fromdirect access to bacteria.

Methods to remove biofilm include ultrasonic debridement, topicalantimicrobials, suction, and surface cleansing. Each of these methodsalone treat an aspect of biofilm. For example, ultrasonic debridement ofwounds has proven to be the most effective mechanism in disrupting anddebulking a majority of the biofilm formation. Yet even in thispreferred method, biofilm debris can be left behind to propagate.Suction alone has not proven to be effective in removing biofilm, andcan potentially interfere with the operation of other methods likeultrasonic debridement if applied simultaneously.

U.S. Pat. No. 7,608,054 to Soring et al. describes a medical treatmentapparatus that combines an ultrasound sonotrode with a suction sheath.The fixed position between the tip of the suction and the tip of thesonotrode only allows for one simultaneous operation. In particular thisapproach is limited due to the potential interference of the suction tipduring the ultrasonic debridement operation.

U.S. Pat. No, 7,522,955 B2 to Rontal et al. describes a method andapparatus for ultrasonic cleaning of biofilm coated surfaces for sinuscavities within a human head. The method describes an ultrasonicapplication in combination with irrigation and suction that is designedto not remove any of the surrounding underlying tissue. This differssignificantly from an ultrasonic debridement of a wound bed, whichrequires the removal of tissue in combination with biofilm. Thus theultrasonic probe needs to operate in a cavitation mode at the surface ofa wound, causing destruction of the biofilm.

Methods of mechanical removal of biofilm in wounds alone have proven tobe inadequate. What does not exist and what would be beneficial to themarket is an ultrasonic probe or instrument assembly which permitsimplementation of an improved method to remove biofilm and prevent itfrom reforming in order to allow wounds to heal.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improvedultrasonic probe and/or instrument assembly.

A more particular object of the present invention is to provide such anultrasonic probe and/or instrument assembly that permits execution of animproved method to inhibit biofilm formation in order to allow wounds toheal more expeditiously.

A related object of the present invention is to provide an improvedmethod for wound debridement or biofilm removal.

Although every feature of the invention is attained in at least oneembodiment of the invention, there is not necessarily any one embodimentthat achieves all of the objects of the invention.

SUMMARY OF THE INVENTION

An ultrasonic surgical probe comprises, in accordance with the presentinvention, an elongate shaft having a distal end portion with alongitudinal axis and a probe head that is enlarged to extend laterallyor transversely in two opposed directions relative to the shaft and theaxis. The head is formed with a recess or cavity facing laterally in athird direction relative to the shaft and the axis. Where the head isconceptualized as lying in a plane, owing to its lateral enlargement orextension, the recess or cavity faces in a direction perpendicular tothat plane. The recess or cavity is defined in part by an inclined flooror base surface contiguous at a proximal end with the shaft. The recessor cavity is defined in part by a peripheral wall extending only partwayaround the recess or cavity, along a distal side and two lateral sidesthereof. The cavity or recess is closed on a proximal side by theinclined surface and the shaft.

Pursuant to further features of the present invention, the recess orcavity is further defined by an additional floor or base surface locateddistally of the inclined floor or base surface. The additional floor orbase surface is planar or flat and oriented parallel to the axis.Preferably, the inclined floor or base surface is also planar or flat.

The distal, additional floor or base surface and the proximal, inclinedfloor or base surface are preferably adjacent and contiguous with oneanother.

Pursuant to further features of the present invention, the probe head isprovided in at least one of the inclined floor or base surface and theadditional floor or base surface with at least one first opening spacedfrom the peripheral wall. The opening permits the egress of pressurizedfluid from the recess or cavity into a space surrounding the probe head,exemplarily into a channel in a sheath that surrounds the probe. Thepressurized fluid is liquid irrigant which serves to cool the surfacesof the probe head, particularly including those surfaces that contacttissue during an ultrasonic debridement or biofilm removal procedure.The pressurized fluid is fed into the recess or cavity via an axialchannel or through bore in the probe shaft. The channel or through borehas an outlet port at least partially in or at the inclined floor orbase surface.

Preferably, the probe head is provided with a second opening or throughhole in the peripheral wall at a distal end of the probe head. A groovemay be formed in the floor of the recess or cavity, with the firstopening or through hole located in the groove, the groove extending tothe second opening or through hole.

The groove may be formed during manufacture during the drilling of aprobe blank to form the channel in the shaft. The inclined floor or basesurface and the additional floor or base surface are subsequently formedby machining one side of the head of the blank. This machining opens aside of the channel in the head and thereby generates the groove.

Pursuant to other features of the present invention, the peripheral wallof the recess or cavity includes a cylindrical section on the distalside of the recess or cavity and further includes two linear sections onthe lateral sides of the recess or cavity. The peripheral wall thus hasa U-shaped plan or configuration.

In accordance with another feature of the present invention, theperipheral wall is provided with a beveled surface, on a side of theperipheral wall opposite the recess or cavity, and has a flat terminaledge in a plane parallel to the axis. The flat terminal edge or rimenables the peripheral wall to transmit ultrasonic vibratory energy intothe tissues at a surgical site during a debridement or biofilmelimination procedure.

It is to be noted that the multiple openings in the head, one in thefloor and one in on the distal portion of the peripheral wall,facilitate the flow of liquid irrigant in part to optimize cooling ofthe peripheral wall and the tissues at the surgical site, thus reducingif not eliminating damage to the healthy tissue which remains after thedebridement procedure. The floor geometry of the recess or cavity in theprobe head acts to deflect and guide removed tissue fragments from therecess or cavity, thereby inhibiting if not completely preventing theclogging of the openings in the probe head. In addition, the flow ofliquid irrigant or coolant into the recess or cavity through the channelor bore in the shaft and out through the openings in the floor and theperipheral wall help move the separated tissue fragments along the floorsurfaces and out of the recess or cavity. The floor structure of therecess or cavity assists in maintaining desired cooling for longerperiods of time.

A surgical instrument assembly comprises, in accordance with the presentinvention, an ultrasonic probe having an operative tip, anelectromechanical transducer operatively connected to the probe forgenerating an ultrasonic standing wave in the probe, and at least onesheath or sleeve disposed about the probe and defining at least a firstsuction port at a distal end of the probe, proximate the operative tipthereof, and a second suction port spaced from the distal end of theprobe. The probe comprises (A) an elongate shaft having a distal endportion with a longitudinal axis and (B) a probe head that is enlargedto extend laterally or transversely in two opposed directions relativeto the shaft and the axis, the head having a recess or cavity facinglaterally in a third direction relative to the shaft and the axis. Therecess or cavity is defined in part by an inclined floor or base surfacecontiguous at a proximal end with the shaft and in part by a peripheralwall extending only partway around the recess or cavity, along a distalside and two lateral sides thereof. The cavity or recess is closed on aproximal side by the inclined surface and the shaft.

The at least one sheath or sleeve is preferably exactly one sheath orsleeve. Optionally, the sheath or sleeve is longitudinally slidablerelative to the probe to shift between a distal position and a proximalposition.

The inclined floor or base surface of the probe cavity is planar or flatand the recess or cavity is further defined by an additional floor orbase surface located distally of the inclined floor or base surface, theadditional floor or base surface being planar or flat and orientedparallel to the axis.

The probe head is provided with a first opening or through hole in thefloor of the recess or cavity, spaced from the peripheral wall. Theprobe head is provided with a second opening or through hole in theperipheral wall. The probe head may be provided in the floor of therecess or cavity with a groove. In that case, the first opening orthrough hole is located in the groove while the groove extends to thesecond opening or through hole.

The peripheral wall preferably includes a cylindrical section on thedistal side of the recess or cavity and further includes two linearsections on the lateral sides of the recess or cavity, so that theperipheral wall has a U-shaped configuration.

The peripheral wall is preferably provided with a beveled surface, on aside of the peripheral wall opposite the recess or cavity, and has aflat terminal edge in a plane parallel to the axis. The bevel tapers theperipheral wall towards the flat terminal edge or rim.

Pressurized coolant liquid enters the recess or cavity in the probe headfrom the channel or bore in the instrument shaft and exits in partthrough the openings in the floor or base and the semi-cylindricalportion of the peripheral wall. The diameters of the channel and theopenings in the probe head, as well as the pressure of the fluid and themagnitude of applied suction must be taken into account in optimizingthe rate of coolant flow so that the entire probe head is maintainedwithin a desirable temperature range.

A surgical method in accordance with the present invention utilizes anultrasonic surgical probe comprising an elongate shaft having a distalend portion with a longitudinal axis and further comprising a probe headthat is enlarged to extend laterally or transversely in two opposeddirections relative to the shaft and the axis. The head has a recess orcavity facing laterally in a third direction relative to the shaft andthe axis, and the recess or cavity is defined in part by an inclinedfloor or base surface contiguous at a proximal end with the shaft. Therecess or cavity is also defined in part by a peripheral wall extendingonly partway around the recess or cavity, along a distal side and twolateral sides thereof, the cavity or recess being closed on a proximalside by the inclined surface and the shaft. The method comprisesmanipulating the probe to press the head and particularly at least aportion of the peripheral wall into tissue at a surgical site. Whilecontinuing to press the head and the portion of the peripheral wall intothe tissue, one draws the probe and concomitantly the portion of theperipheral wall in a proximal direction across the tissue, substantially(mostly) parallel to the surgical site. During that drawing process,ultrasonic vibrations are conducted into the probe. Tissue is separatedfrom the surgical site by the drawing of the probe and the ultrasonicvibrating thereof. Upon the separating of the tissue, the separatedtissue is deflected or moved out of the recess or cavity in part bycontact of the separated tissue with the inclined floor or base surface.During the drawing of the probe, an irrigation liquid is fed to therecess or cavity via a longitudinal channel or bore in the probe shaft.The irrigation liquid serves to cool the probe head and assists inmoving the separated tissue out of the recess or cavity. Flow of theliquid irrigant/coolant is maintained in part where the probe head isformed with at least one opening or through hole through which theliquid is aspirated into a surrounding sheath or sleeve. Thecross-sectional areas of the channel or bore and the opening(s) in theprobe head, as well as the pressure f liquid feed and the degree ofsuction are selected in concert to ensure adequate cooling of the probehead.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial longitudinal cross-sectional view of a device fordebriding or removing biofilm from a wound site.

FIG. 2 is a schematic right side, top and front perspective view of thedevice of FIG. 1.

FIG. 3 is an exploded right side, top and front perspective view of aprobe and sheath included in the device of FIGS. 1 and 2.

FIG. 4 is an exploded left side, top, and rear perspective view of theprobe and sheath of FIGS. 1-3.

FIG. 5 is a rear elevational view of the probe and sheath of FIGS. 1-4.

FIG. 6 is a partial cross-sectional view, similar to FIG. 1, taken alongline VI-VI in FIG. 5.

FIG. 7 is a top plan view of an ultrasonic surgical probe in accordancewith the present invention.

FIG. 8 is a front end elevational view of the probe of FIG. 7.

FIG. 9 is a right side elevational view of the probe of FIGS. 7 and 8.

FIG. 10 is a right, top and rear isometric view of a head of the probeof FIGS. 7-9.

FIG. 11 is a right, bottom and front isometric view of the probe head ofFIG. 10.

FIG. 12 is a right, top and front isometric view of the probe head ofFIGS. 10 and 11.

FIG. 13 is a top, front and let side isometric view of the probe head ofFIGS. 10-12.

FIG. 14 is a side elevational view of a sheath for an ultrasonicsurgical instrument assembly in accordance with the present invention.

FIG. 15 is a bottom, and right side isometric view of an instrumentassembly including the sheath of FIG. 14 and the probe of FIGS. 7-13.

FIG. 16 is a schematic and diagrammatic longitudinal cross-sectionalview, on an enlarged scale, of a distal end portion of the instrumentassembly of FIGS. 14 and 15.

FIG. 17 is a schematic and diagrammatic longitudinal cross-sectionalview similar to FIG. 16, showing use of the instrument assembly indebriding or removing tissue and biofilm from a wound site, withdirectional arrows indicating tissue fragment transport.

FIG. 18 is a schematic and diagrammatic longitudinal cross-sectionalview, on a smaller scale, showing a larger distal end portion of theinstrument assembly of FIGS. 14 and 15 than visible in FIGS. 16 and 17and with directional arrows indicating flow of liquid coolant orirrigant.

FIG. 19 is a schematic and diagrammatic longitudinal cross-sectionalview identical to FIG. 16, with directional arrows to representirrigation liquid flow paths.

DETAILED DESCRIPTION

As depicted in FIGS. 1-6, a surgical device 300 for debriding orremoving tissue and biofilm from a wound site comprises an ultrasonicprobe 302 which is attached at a proximal end via threaded connector 304to a driver 306 is operatively connected to a generator of vibratoryenergy, typically a piezoelectric transducer array (not shown). Both thedriver 306 and the piezoelectric transducer are located in a handpiecewhich has a cover or housing (not shown) connected to a casing 308.Probe 302 tapers down on a distal side to a distal end section 310. Itis to be noted that the terms “horn” and “probe” are used synonymously.

Driver 306 and probe 302 are formed with mutually aligned axial channelsor bores 312 and 314 that define a lumen (not separately designated) forthe delivery of irrigant to a distal end aperture 316 in probe hornsection 310, as indicated by flow arrows 318.

Surgical device 300 further includes a rigid sheath 320 that isshiftably mounted to casing 308 to vary a position of a distal tip 322of the sheath relative to a distal tip or end face 324 of probe 302.Sheath 320 includes a cylindrical rear section 326 and a rectangularlyprismatic forward section 328, which correspond geometrically tocross-sections of horn 310 and a proximal portion 330 of probe, 302,respectively.

Together with an outer surface (not designated) of probe horn 310,forward sheath section 328 defines a forward or distal channel orconduit 332, which is rectangular in cross-section. Together with anouter surface (not designated) of proximal probe portion 330, rearsheath section 326 defines a rearward or proximal channel or conduit334, which is circular in cross-section. At a distal end, rearwardchannel 334 expands to an enlarged space 336 owing to the tapering ofthe probe at 338.

Sheath 320 is provided with an arm 340 that is connected at a forward ordistal end to forward section 326 and is angled outwardly at a proximalside. Sheath arm 340 includes a main aspiration channel 342 thatcommunicates at a distal end with forward channel 332. At a moreproximal location, aspiration channel 342 of arm 340 communicates withrearward channel 334 and more particularly with enlarged space 336. At aproximal end, arm 340 is provided with an undercut connector port 344which receives a resilient aspiration tube 346 in a friction fit.Aspiration tube 346 is fastened to casing 308 via a pair of clips 348each formed with a pair of slotted annular rings 350 and 352 forreceiving casing 308 and aspiration tube 346, respectively.

At a forward or distal end, probe horn 310 is formed with one or moreapertures or cross-bores 354 and 356 that communicate on an inner sidewith channel or lumen 314 and on an outer side with forward channel 332.At a rear end, rear section 326 of sheath 320 is inserted betweenproximal probe portion 330 and a distal end of casing 308. An O-ringseal 358 is provided between casing 308 and an outer surface of sheathrear section 326.

A distal end of horn section 310 is formed into a probe head 360 that isextended in a traverse dimension, orthogonally to a longitudinal axis ofthe probe 302. Head 360 may particularly take a form disclosed in U.S.patent application Ser. No. 14/172,566, Publication No. 2015/0216549,the disclosure of which is incorporated by reference herein. Inparticular, head 360 includes a plurality of teeth 362 arranged in twomutually parallel rows along opposing edges or sides of the distal endface 324 of the probe head.

As indicated above, sheath 320 is slidable or longitudinally shiftablerelative to probe 302 so as to be continuously adjustable as to axial orlongitudinal position relative to probe head 360 anywhere from a fullyextended position, where the distal tip 322 of sheath 320 is essentiallycoplanar with the distal end face 324 of probe head 360, to a retractedposition where at least the teeth 362 of probe head 360 are fullyexposed. O-ring 358 enables the adjustable positioning of sheath 320.

Apertures or cross-bores 354 and 356 serves as bypass holes, regardlessof the relative longitudinal positioning of sheath 320 and probe 302. Avacuum under-pressure applied to the internal spaces of sheath 320,i.e., aspiration channel 342, forward channel 332, and rearward channel334, by a suction source (not shown) enables the capturing and removalof most of the irrigant that is delivered through central channel 314(flow arrows 318). Accumulation of irrigant within sheath 320,especially when the device is used in a predominantly verticalorientation, is prevented by the provision of two suction pathways,namely, between aspiration channel 342 and each of the forward channel332 and rearward channel 334. Irrigant not captured via a distal pathwayis captured in a proximal pathway.

Where tissue fragments are small enough to be aspirated through the gapbetween the probe 302 and the sheath 320, clogging is prevented bydesigning the aspiration pathway of channel 324 to gradually increase incross-sectional area from the probe-sheath gap at the distal end of theinstrument all the way to the aspiration line. A vent port 364 may beprovided in the rear sheath section 326 to reduce the magnitude ofvacuum-generated pull force acting on the tissue which is driven towardsand into the probe-sheath gap during debridement.

Matching or cooperating features 366 and 368 are respectively disposedon the outer side of the probe 302 and the inside of rear sheath section326, in close proximity to a nodal plane or the probe, to facilitateprobe-sheath alignment. This minimizes the chances of a probe-sheathcontact at the points of maximum vibratory motion (antinodes),particularly at end face 324 of probe head 360. Due to their placementat a location of minimal vibratory displacement, e.g., the junction 370between cylindrical probe portion 330 and tapering probe section 338,the alignment features 366 and 368 allow for the probe-sheath contactnecessary for preventing or minimizing the unwanted interaction in thearea of maximum vibratory displacement.

FIGS. 7-13 depict an ultrasonic surgical probe 102 that may be usedinstead of probe 302 for debriding tissue or removing biofilm from awound site. Probe 102 comprises an elongate shaft 104 having an enlargedproximal end portion 106 with a screw-type coupling 108 for connectionto a source of ultrasonic mechanical vibratory energy. Shaft 104 has adistal end portion 110 with a longitudinal axis 112 and a probe head 114that is enlarged to extend laterally or transversely in two opposeddirections (arrows 116, 118) relative to shaft 104 and axis 112. Head114 is formed with a recess or cavity 120 facing laterally in a thirddirection (arrow 122) relative to shaft 104 and axis 112. Where head 114may be seen as lying in a plane defined by axis 112 and extensiondirections 116 and 118, recess or cavity 120 faces in direction 122perpendicular to that plane. Recess or cavity 120 is defined in part byan inclined floor or base surface 124 contiguous at a proximal end withshaft 104. Recess or cavity 120 is further defined in part by aperipheral wall 126 extending only partway around the recess or cavity,with a cylindrical wall portion 128 along a distal side of head 114 andtwo linear or planar wall sections 130, 132 along lateral sides thereof.Peripheral wall 126 thus has a U-shaped plan or configuration. Recess orcavity 120 is closed on a proximal side by inclined surface 124 andshaft 104.

Recess or cavity 120 is further defined by an additional floor or basesurface 134 located distally of inclined floor or base surface 124.Additional floor or base surface 134 is planar or flat and orientedparallel to shaft axis 112. Preferably, inclined floor or base surface124 is also planar or flat. Floor or base surfaces 124 and 134 arepreferably adjacent and contiguous with one another.

Probe head 114 is provided in at least one opening 136 in eitherinclined floor surface 124 and/or parallel floor surface 134. Opening136 is spaced from the peripheral wall 126. Opening 136 permits theegress of pressurized fluid from recess or cavity 120 into a spacesurrounding probe head 114, exemplarily into a channel 138 in a sheath140 that surrounds the probe 102 (see discussion above with reference tocross-bores 354 and 356 shown in FIG. 1 and description hereinbelow withreference to FIGS. 14 et seq.). The pressurized fluid is a liquidirrigant for cooling the surfaces of the probe head 120 particularlyincluding surfaces of peripheral wall 126 and other surfaces thatcontact tissue at a surgical site during an ultrasonic debridement orbiofilm removal procedure. The pressurized fluid is fed into recess orcavity 120 via an axial channel or through bore 142 in probe shaft 104.Channel or through bore 142 has an outlet port 144 at least partially inor at inclined floor or base surface 124.

Preferably, probe head 114 is provided with a further opening or throughhole 146 in peripheral wall 126 at a distal end of the probe head,particularly in cylindrical wall section 128. A groove 148 is formed infloor surfaces 124 and 134 of recess or cavity 120, with opening orthrough hole 136 located in the groove, the groove extending tocylindrical wall section 128 and particularly to opening or through hole146 therein.

Groove 148 is typically formed during manufacture during a drilling of aprobe blank (not separately shown) to form channel or bore 142 in probeshaft 104. Inclined floor or base surface 124 and the distal floor orbase surface 134 are subsequently formed by machining one side of thehead of the blank. This machining opens a side of the channel in thehead and thereby generates groove 148.

Peripheral wall 126 is provided with a beveled surface 150, on a side ofthe peripheral wall opposite recess or cavity 120, and has a flatterminal edge 152 in a plane parallel to axis 112 and the plane of head114. The flat terminal edge or rim 152 enables the peripheral wall 126to transmit ultrasonic vibratory energy into the tissues at a surgicalsite during a debridement or biofilm elimination procedure.

It is to be noted that the multiple openings 136, 146 in the probe head114, one in the floor 124, 134 and one in on the distal portion 128 ofperipheral wall 126, facilitate the flow of liquid irrigant in part tooptimize cooling of the peripheral wall and the tissues at the surgicalsite, thus reducing if not eliminating damage to the healthy tissuewhich remains after the debridement procedure.

The floor geometry of recess or cavity 120 in probe head 114 acts todeflect and guide removed tissue fragments from the recess or cavity,thereby inhibiting if not completely preventing the clogging of theopenings 136, 146 in the probe head. In addition, the flow of liquidirrigant or coolant into the recess or cavity 120 through the channel orbore 142 in shaft 104 and out through the openings 136, 146 in the floor124, 134 and the peripheral wall 126 help move the separated tissuefragments along the floor surfaces 134, 124 and out of the recess orcavity 120. The floor structure of recess or cavity 120 assists inmaintaining desired cooling for longer periods of time.

FIGS. 14-19 depict a surgical instrument assembly incorporating probe102 and including sheath or sleeve 140 disposed about probe 102. Asshown in FIGS. 14 and 15, sheath 140 includes an eccentric suction arm154 extending at an angle away from a distal end of the sheath. Aconnector 156 provided at a proximal end of the suction arm 154 isforce-fit into a distal end of a length of vacuum tubing 158 that isfurther attached to the sheath 140, as well as to a transducer housing160 via a plurality of spring clips 162. FIG. 15 also shows a liquidconduit 164 coaxial with probe axis 112 and an electrical cable 166 thatprovides an ultrasonic-frequency power signal to the transducer disposedinside housing or handpiece 160.

As described hereinabove with reference to FIGS. 1-6, sheath or sleeve140 defines at least a first suction port 168 at a distal end of theprobe, proximate the operative tip or head 114 thereof, and a secondsuction port 170 (FIG. 18) spaced back from the distal end of the probe.The relationship between probe 102 and sheath or sleeve 140 is analogousto that described above with reference to FIGS. 1-6.

Sheath or sleeve 140 is preferably exactly one sheath or sleevelongitudinally slidable relative to probe 102 to shift between a distalposition and a proximal position. Sheath or sleeve 140 has a distal endwall section 172 that is disposed transversely or perpendicularly to theprobe axis 112 (which is co-linear or co-incident with an axis of sheath140). Distal end wall section 172 facilitates collection and extractionof liquid irrigant that exits probe head 114 and more particularlycavity or recess 120 via opening or through hole 146 in cylindricalsection 128 of peripheral wall 126. The purpose of irrigant collectionand extraction is two-fold: to prevent the irrigant from overflowing asurgical site and the operating table and to facilitate temperaturecontrol.

Pressurized coolant liquid enters recess or cavity 120 in probe head 114from channel or bore 142 in instrument shaft 104, as indicated by arrows174 in FIGS. 17-19, and exits in part through opening 136 in floor orbase surface 124 or 134, as represented by arrows 176, and opening 146in semi-cylindrical portion 128 of peripheral wall 126 (arrows 178).Some of the irrigant that enters recess or cavity 120 from channel orbore 142 forms a slurry with tissue fragments that are removed from asurgical site 180 (FIG. 17) during a debridement or biofilm-removalprocedure in which the ultrasonically vibrating probe head 114 andparticularly rim or surface 152 thereof is pressed into the tissue, asindicated by a first force arrow 182 (FIG. 17), and then dragged in aproximal direction as represented by a second force arrow 184. In thisoperation, the slurry of irrigant and tissue fragments moves in circularflow patterns 186 guided by inclined floor or base surface 124 of probehead 114. The tissue fragments are thus deflected out of the cavity 120and away from openings 136 and 146, thereby delaying if not preventingclogging of the openings and the suction path inside eccentric suctionarm 154 of sheath 140. The diameters or cross-sectional areas of channelor bore 142 and of openings 136 and 146 in probe head 114, as well asthe pressure of the fluid (174) and the magnitude of applied suction(negative-sign symbols 188) must be taken into account in optimizing therate of coolant flow so that the entire probe head 114 is maintainedwithin a desirable temperature range.

During the pressing (182) and drawing (184) of probe 144 during adebridement or biofilm-removal procedure, irrigation liquid or coolantis fed to recess or cavity 120 via channel or bore 142 in probe shaft104. The irrigation liquid serves to cool the probe head 114 and assistsin moving the separated tissue via slurry flow 186 out of recess orcavity 120. Flow of the liquid irrigant/coolant is maintained in part byopenings or through holes 136, 146 through which the liquid is aspiratedinto sheath or sleeve 140.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. An ultrasonic surgical probe comprising: anelongate shaft having a distal end portion with a longitudinal axis; anda probe head that is enlarged to extend laterally or transversely in twoopposed directions relative to said shaft and said axis, said headhaving a recess or cavity facing laterally in a third directionorthogonal or transverse to said shaft and said axis, said recess orcavity being defined in part by an inclined floor or base surfacecontiguous at a proximal end with said shaft, said recess or cavitybeing further defined in part by a peripheral wall extending onlypartway around said recess or cavity, along a distal side and twolateral sides thereof, said cavity or recess being closed on a proximalside by said inclined surface and said shaft.
 2. The surgical probedefined in claim 1 wherein said recess or cavity is further defined byan additional floor or base surface located distally of said inclinedfloor or base surface, said additional floor or base surface beingplanar or flat and oriented parallel to said axis.
 3. The surgical probedefined in claim 2 wherein said inclined floor or base surface is planaror flat.
 4. The surgical probe defined in claim 3 wherein saidadditional floor or base surface and said inclined floor or base surfaceare adjacent and contiguous with one another.
 5. The surgical probedefined in claim 2 wherein said probe head has at least one opening orthrough hole in at least one of said inclined floor or base surface andsaid additional floor or base surface, said opening or through holecommunicating with said recess or cavity.
 6. The surgical probe definedin claim 5 wherein said opening or through hole is a first opening orthrough hole and is spaced from said peripheral wall, said probe headbeing provided with a second opening or through hole in a distal endportion of said peripheral wall.
 7. The surgical probe defined in claim6 wherein said probe head is provided in said cavity with a groove, saidfirst opening or through hole being located in said groove, said grooveextending along said additional floor or base surface to said secondopening or through hole.
 8. The surgical probe defined in claim 7wherein said shaft is provided with an axial channel or through bore,said groove being continuous and coaxial with said channel or throughbore.
 9. The surgical probe defined in claim 5 wherein said shaft isprovided with an axial channel or through bore having an outlet oropening into said recess or cavity.
 10. The surgical probe defined inclaim 1 wherein said peripheral wall includes a cylindrical section onsaid distal side of said recess or cavity.
 11. The surgical probedefined in claim 10 wherein said peripheral wall further includes twolinear sections on said lateral sides of said recess or cavity, saidperipheral wall having a U-shaped plan.
 12. The surgical probe definedin claim 11 wherein said peripheral wall is provided with a beveledsurface, on a side of said peripheral wall opposite said recess orcavity, and has a flat terminal edge in a plane parallel to said axis.13. A surgical instrument assembly comprising: an ultrasonic probehaving an operative tip; an electromechanical transducer operativelyconnected to said probe for generating an ultrasonic standing wave insaid probe; and at least one sheath or sleeve disposed about said probeand defining at least a first suction port at a distal end of saidprobe, proximate said operative tip, and a second suction port spacedfrom said distal end of said probe, wherein said probe comprises: anelongate shaft having a distal end portion with a longitudinal axis; anda probe head that is enlarged to extend laterally or transversely in twoopposed directions relative to said shaft and said axis, said headhaving a recess or cavity facing laterally in a third direction relativeto said shaft and said axis, said recess or cavity being defined in partby an inclined floor or base surface contiguous at a proximal end withsaid shaft, said recess or cavity being defined in part by a peripheralwall extending only partway around said recess or cavity, along a distalside and two lateral sides thereof, said cavity or recess being closedon a proximal side by said inclined surface and said shaft.
 14. Thesurgical instrument assembly defined in claim 13 wherein said inclinedfloor or base surface is planar or flat and said recess or cavity isfurther defined by an additional floor or base surface located distallyof said inclined floor or base surface, said additional floor or basesurface being planar or flat and oriented parallel to said axis.
 15. Thesurgical instrument assembly defined in claim 14 wherein said probe headis provided in at least one of said inclined floor or base surface andsaid additional floor or base surface with a first opening or throughhole communicating with said recess or cavity, said first opening orthrough hole being spaced from said peripheral wall, said probe headbeing provided with a second opening or through hole in said peripheralwall.
 16. The surgical instrument assembly defined in claim 13 whereinsaid peripheral wall includes a cylindrical section on said distal sideof said recess or cavity, said peripheral wall further including twolinear sections on said lateral sides of said recess or cavity, saidperipheral wall having a U-shaped plan.
 17. The surgical instrumentassembly defined in claim 16 wherein said peripheral wall is providedwith a beveled surface, on a side of said peripheral wall opposite saidrecess or cavity, and has a flat terminal edge in a plane parallel tosaid axis.
 18. The surgical instrument assembly defined in claim 13wherein said first suction port and said second suction port aredifferent openings in said at least one sheath or sleeve.
 19. A surgicalmethod utilizing an ultrasonic surgical probe comprising an elongateshaft having a distal end portion with a longitudinal axis and furthercomprising a probe head that is enlarged to extend laterally ortransversely in two opposed directions relative to said shaft and saidaxis, said head having a recess or cavity facing laterally in a thirddirection relative to said shaft and said axis, said recess or cavitybeing defined in part by an inclined floor or base surface contiguous ata proximal end with said shaft, said recess or cavity being defined inpart by a peripheral wall extending only partway around said recess orcavity, along a distal side and two lateral sides thereof, said cavityor recess being closed on a proximal side by said inclined surface andsaid shaft, the method comprising: manipulating said probe to press saidhead and particularly at least a portion of said peripheral wall intotissue at a surgical site; while continuing to press said head and saidportion of said peripheral wall into the tissue, drawing said probe andconcomitantly said portion of said peripheral wall across the tissue,parallel to the surgical site; during the drawing of said probe,conducting ultrasonic vibrations into said probe; separating tissue fromthe surgical site by an ultrasonic vibrating of said probe head and saidperipheral and by the drawing of said probe; upon the separating of thetissue, deflecting the separated tissue out of said recess or cavity inpart by contact of the separated tissue with said inclined floor or basesurface; and during the drawing of the probe, feeding an irrigationliquid to said recess or cavity via at least one opening or through holein said probe head.